Immobilized cell microchannel bioreactor for evaluating fermentation characteristics of mixed substrate consumption and product formation

2012 ◽  
Vol 47 (6) ◽  
pp. 1011-1015 ◽  
Author(s):  
Tae Young Seo ◽  
Ki Won Eum ◽  
Sung Ok Han ◽  
Seung Wook Kim ◽  
Ji Hyeon Kim ◽  
...  
2014 ◽  
Vol 633-634 ◽  
pp. 545-549
Author(s):  
Hong Li Xiao ◽  
Lan Zhang Chong ◽  
Fei Li Hang ◽  
Wang Yong

In this paper, the nonlinear dynamic system of microbe continuous fermentation products 1,3-propanediol (1,3-PD) is rewritten by improving the specific cellular growth rate, specific substrate consumption rate and specific product formation rate. Firstly, under the condition of substrate glycol excess and active trans-membrane transport, according to the dynamic behavior the fermentation process, we consider the glycerol and 1,3–PD concentration within the cell, and improve the specific cellular growth rate, specific substrate consumption rate and specific product formation rate, then rewrite the dynamic system of microbial continuous fermentation process. Secondly, taking the dynamic system as main constraint condition, we establish the parameter identification model and prove the existence of the optimal solution. Lastly, the numerical results calculated by particle swarm algorithm show that the improved model is suitable for describe the dynamic behavior of 1,3-PD, but is not accurate enough for by-products.


2020 ◽  
Author(s):  
Arnaldo Silva Oliveira ◽  
Juan C. B. Neto ◽  
Igor J. B. Santos ◽  
Edson R. Nucci

Abstract The Z- and Laplace transforms are mathematical techniques applied to solve difference equations and differential equations, respectively. Mathematical models used to describe cell growth, substrate consumption and product formation in bioprocesses can be represented by these types of equations. Thus, in this work, the fermentation process of the yeast Saccharomyces cerevisiae was modeled using different models from the literature, and the Z- and Laplace transforms were applied to solve the equations. Once the equations were solved, the models were represented in state space and simulated in Octave® software. Finally, the models were compared to experimental data from previous studies and to each other. Verhulst was the model that best described the process, with an average error of 4.74% for cell growth and 13.9% for substrate consumption. This work is unprecedented since no works that use the Z transform and discrete models for the representation of fermentation of this yeast were found in the literature. Even more importantly, this work proved that discrete-time models can be applied to bioprocesses with the same precision as continuous-time models.


2013 ◽  
Vol 781-784 ◽  
pp. 647-652
Author(s):  
Shuang Gao ◽  
Ling Hua Zhang ◽  
Qing Chen ◽  
Lin Bai ◽  
Ya Jun Lang

Ectoine had important physiological functions and superior potential applications, so the study of ectoine was extensively attented. This article was related to kinetic models of cell growth, product formation and substrate consumption, which was not only established according to the characteristics of ectoine batch fermentation by Halomonas salina DSM 5928 but also obtained the kinetic parameters by the nonlinear fitting method in the Microcal Origin software. Logistic, Luedeking-Piret and Luedeking-Piret-like equations was applied to analyze the cell growth, the ectoine formation and the substrate consumption by the kinetic model,respectively. The results between calculated values and experimental data were coincident. By fitting, correlation coefficients R2 were ≥ 0.989. The fermentation conditions of ectoine were analyzed according to the model. The results showed that ectoine productivity (0.28 g/L/h) was the highest when initial monosodium glutamate concentration (S0) was 60 g/L. However, when S0 was 80 g/L, the ectoine concentration was maximal, i.e., 7.59 g/L. The research suggested that ectoine formation belonged to the mixed kinetic mechanism of cell growth and biomass concentration, while the ectoine production mainly depended on instantaneous biomass concentration. The fermentation method for improving ectoine concentration was further proved. The established kinetic model will be of significant value to provide the optimal conditions of present process.


1994 ◽  
Vol 57 (4) ◽  
pp. 341-344 ◽  
Author(s):  
A. PEREZ CHAIA ◽  
A. M. STRASSER DE SAAD ◽  
A. PESCE DE RUIZ HOLGADO ◽  
G. OLIVER

Lactobacillus helveticus and Propionibacterium acidipropionici were grown in pure and mixed cultures in a complex medium to assess the associative interaction. The specific growth rates, substrate consumption coefficient, substrate utilization and product formation rates were determined in each case. Propionibacterium acidipropionici utilized glucose preferably when it grew in a medium containing a mixture of glucose and lactate. Its growth rate was higher on glucose than on lactate in pure culture. However, lactic acid was the substrate utilized by propionibacteria in the associative growth. The fast pH reduction produced by the growth of lactobacilli and the slow lactate utilization by propionibacteria in mixed culture determined the inhibition of propionic acid bacteria in associative growth.


2015 ◽  
Vol 17 (2) ◽  
pp. 114 ◽  
Author(s):  
J. Jasman ◽  
Irfan Dwidya Prijambada ◽  
Chusnul Hidayat ◽  
Donny Widianto

This study was aimed to compare the ability of some yeast strains to consume sugars (sucrose, glucoseand fructose) and to convert them into ethanol during fermentation. The results of this comparison will be thebasis of considerations in choosing the right strain to be used as a mixed culture to increase the productionof ethanol from substrate containing a mixture of sucrose, glucose and fructose, such as juice of cane andsweet sorghum. The study was conducted using fermentation in substrate consisting of glucose, fructose,and sucrose separately, glucose-fructose mixture, and glucose-fructose-sucrose mixture using some yeaststrains: FNCC3012, OUT7009, OUT7027, OUT7055, OUT7080, OUT7096, OUT7903, OUT7913, and OUT7921.Following the fermentation, analysis of the produced ethanol and the remaining sugar was conducted. Theresults of study indicated that the strains with the highest substrate consumption were OUT7921, OUT7096,OUT7055, OUT7027, and OUT7913 for glucose, fructose, glucose-fructose mixture, sucrose, and glucosefructose-sucrose mixture, respectively. Strains that produced highest concentration ethanol were OUT7096 inglucose and sucrose substrates, OUT7921 in substrate of glucose-fructose mixture and sucrose, OUT7913 insubstrate of glucose-fructose-sucrose mixture. Upon consideration of each strain capacity, both in consumingsugar and producing ethanol, the recommended strains for use in mixed culture in bioethanol fermentationusing mixed substrate of glucose, fructose and sucrose are OUT7096, OUT7913, and OUT7921.


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